Numerous window and window frame types are available on the market. Screens either install on a building inside or outside (the building defining an opening for a window and screen between the inside and outside), and appear either in front of (meaning disposed toward the building inside) or behind (meaning disposed toward the building outside) the window. There are different window types depending on the frame, including slider, double, and single hung windows. Any screen appearing behind a window typically requires installation from outside the building. Prior art screen systems permit installation and removal from inside the building, but require pivoting metal clips. These clips can easily fall out of their guide slots, be lost, and are cumbersome to operate. The clips also have pointy ends, posing a safety hazard.